


Jealousy

by usefultrash



Category: Supernatural
Genre: A/B/O, Alpha - Freeform, Binding With Sports Bras, Cis Male/Trans Male, Destiel - Freeform, FTM, Gay, Gay Sex, Gay Trans Male, Hickeys, High School AU, Human AU, Implied Sam/Jessica Smut, Jealousy, Jock - Freeform, M/M, Mating, Mentioned Lesbian Relationship, Self-Lubrication, Slightly dubious consent, Smut, Social Hierarchy, Trans AU, Trans!Castiel, a tiny bit of dysphoria talk, alpha to omega, alpha/beta/omega, beta, destiel sex, destiel smut, nerd, nerd/jock, omega - Freeform, public making out, safe binding, sleepover, slight Breeding Kink, trans male, transgender AU
Language: English
Status: Completed
Published: 2019-04-28
Updated: 2019-04-28
Packaged: 2020-02-09 09:05:15
Rating: Explicit
Warnings: Underage
Chapters: 3
Words: 2,909
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18635056
Author URL: https://archiveofourown.org/users/usefultrash/pseuds/usefultrash
Summary: Cas has always been head over heals for his best friend’s brother.





	1. In My Head

Castiel was never popular. That wasn’t even a secret. Even with close friends, the sweet-scented omega never got noticed much. He was okay with that, too. With all his siblings at home, he was used to blending in with a bunch of kids. 

Cas had many friends, too. All of them pretty similar. All of them were nerds who were very tight-knit and sometimes even shy. But their most important unspoken rule? Never mingle outside the group. 

However dumbass Cas was hooked on a popular boy. The most popular boy in the school: Dean Winchester. The beautiful, powerful alpha would strut around school, different omega on his arm every other day. God, how Cas would get jealous. 

The omega teenager wanted Dean as all his. Cas would dream of the senior alpha knotting him, biting his neck to blood, mating him. He would produce so much slick in one night sometimes, he’d need to change bedsheets. 

All of this was extremely weird on many levels, too. First of all? Dean was probably straight. He would probably be so disgusted at Cas touching himself to the thought of him. Secondly, Dean’s brother, Sam? One Cas’ friends in the group. The omega was literally thinking about banging his best friend’s older brother. And third of all (how could it be any worse?), Castiel was transgender.

The young omega wasn’t sure how Dean would feel. On top of being probably straight, Dean would probably not want to appear in the mind of a person who was expected to be an alpha female. 

Sure, Cas was on hormone blockers, but he did have alpha female mannerisms. Raging jealousy was his main one. The ugly, ugly emotion of jealousy. 

When he saw Dean with a girl, every bone in his body told him that he should ruin her. He should just take what was his and cut her from the picture.

Of course, there were good things about his tendencies, like he was one to first engage a conversation or plan out times to hang out with his friends, but there were times when he scared himself. It could’ve just been his dysphoria, but he swore if was actually an alpha, he’d be more violent than all the other alpha girls. 

Cas just wanted to be just like every other omega male. Even if this society saw them as lesser men, he just wanted more than anything to be exactly omega. He wanted to be the perfect omega for Dean Winchester. He wanted to dress up, look pretty, and smell good for that damned alpha. 

“Castiel,” their teacher, Ms. Kline, snapped him out of his thoughts. Cas looked at her, surprised, “Ma’am?” 

She sighed and everyone let out a stifled giggle. Shit. It was roll call. He buried his face in his hands and sighed. This day was going to be long already.


	2. Sleepover

“Guys!” Charlie ran over to the lunch table. The fiery haired omega jumped in the seat, discarding the lunch bag on the table. She clearly had news. Charlie was a sophomore that was new at the beginning of the year, however, she made herself at home here. 

“This alpha female came up to me in the locker room, right? And totally just like scented me, right there! I mean, I didn’t mind, I liked it. You think we could be mates?”

Sam, a freshman and yes, that Sam, the brother Sam, laughed. “Charlie, you’re sixteen, chill with the mating, okay?”

Cas, however, ignored the reasonable beta. He hunched over the table, having to know all the details. “Who was it? Did you scent her back? How did she smell? How did the others react?” Cas asked her this all at once. 

Charlie blushed, “It was Jo Harvelle—”

Castiel cut her off, “Ms. Harvelle’s daughter?!”

“Yes,” Charlie answered him shortly from being interrupted. “And… After a while I did. She smelled like… Rain and limes.” Charlie turned red and smiled softly, “And all her friends cheered. I think they wanted her to.”

“But Charlie,” Kevin, a low ranking omega, mumbled. “What about the group?”

“Please!” Jessica started. “Let Charlie do what she wants. Why do we even go by social structures like that anymore?” There she went. Jessica was always ranting about the whole alpha/beta/omega structure was stupid and the whole idea of strict groups like this was dumb. Cas had to honestly agree with her on a few levels. He obviously wanted to break the mold of the group and go with that wonderful alpha, Dean.

Cas nodded slightly in agreement to the blonde beta, “Jess is right, Kev. If Charlie finds a good mate with Jo then who cares?”

Sam rolled his eyes. Just like his mate— ahem girlfriend, he was a little critical about how things were set up, “Stop worrying about mates. We’re in high school.”

Cas sighed and rolled his eyes back at the Winchester. Cas just guessed since he was a beta he wouldn’t understand the type of need that was felt by omegas or alphas to find a mate.

“If she wants to mate then she can,” the black haired teenager called him out. “Alphas and omegas have a need to find mates. You’re betas and so you don’t understand.”

Everyone stayed quiet for a moment at the alpha coming out of the omega. Cas sighed and took a bite of his sandwich, tapping his fingers on the table. Sam recovered the situation, all of Cas’ friends knowing how to do that by now.

“Any of you wanna come to my party tonight? It’s at my house and it’s an all night thing,” he looked around at any interested faces. 

“I’ll come,” Charlie smiled. “That sounds awesome. Are we watching a movie or bringing snacks?”

Sam nodded, “Yeah bring blankets and pillows or whatever. Bring enough to get comfy. We’re watching whatever we decide.”

Kevin smiled, “I’ll come. I’ll bring cheesy popcorn.”

Cas inhaled deeply. He thought about staying all night in the house of Dean, his smell filling up the omega’s nostrils. He didn’t know how he could stay a night without filling his pants with slick. He met the expecting eyes of his friends. If he said no he had to explain and… “Okay!” He smiled fakely.

Sam looked at his girlfriend lovingly, “Then we can all go!”

Cas sighed again, great.


	3. Mate Me

Cas stood on the Winchesters’ porch. He hugged a sleeping bag and a big pillow to his chest. A bag was thrown over his shoulder, holding snacks and pajamas for the night. He inhaled and exhaled nervously at the cold, Friday night air. He could already smell Dean. 

He rang the doorbell, waiting on tiptoes for someone to open the door. The lock clicked and it was opened, by holy fuck. It was Dean Winchester. Cas stiffened at the intense alpha smell, staring at the pretty green eyes. 

“Oh, hey, Castiel.” Dean nodded his head. He stepped back to let the boy in, “Jessica is already here.” Dean gave a warm smile to him, making him blush. God, this was going to be a long ass night.

The junior gave a curt nod and walked in past his crush. He looked around the living room, not seeing either of his friends. He threaded his eyebrows together, frowning. He turned to look at Dean from the sound of his voice. 

“They’re in Sam’s room,” he laughed. “I think you should wait to see them.” He then threw himself on the couch, smiling at Cas. 

The black-haired boy sat his stuff next to the couch, knees getting weak. He had to lean on the couch to support himself. He felt something leak from his hole. Jesus Christ, he was producing slick. 

He swallowed, shaking. He knew Dean could smell him. He smelled the alpha’s interest pique and become aroused. He smelled the overwhelming scent of horny alpha. Holy fuck. Yeah, maybe Dean wasn’t as straight as he thought. 

Dean smirked, standing up. He walked over to him slowly, something animalistic about his stride. The light brunette stood over the omega, eyes slitted, lips plumped for the kissing. Dean buried his freckled nose in Castiel’s neck, scenting the omega. 

Cas gasped, squirming. He gripped the omega’s wide shoulders, leaning against his flat chest. “Dean,” he mewled out. 

Dean pulled away, smiling at him, “Cas… You smell so wonderful.” Dean let out a deep and husky moan that made his stomach churn. “Like peaches and honey.” He smirked softly at him, “You can scent me, omega.”

Cas put himself up on his tip-toes, burying his nose in the dappled neck skin. He inhaled deeply, smelling pine and grass. Cas shook more, falling back down on Dean, not even able to stand. 

Dean grabbed his waist, hands running up and down his body. The alpha let his thumbs run up into Cas’ shirt. The omega shuddered, pulling away, “Dean… There’s something I need to tell you.”

Dean cocked his head, his eyes still burning green with lust. Cas loved being finally under the stare, but would he be under that stare for long? 

“I’m trans,” Cas blurted. He looked at his feet, closing his eyes. “I’m trans,” he whispered again. To who? He didn’t know.

Dean inhaled deeply, biting his bottom lip and nodding. “That makes sense,” he let off a slight smirk.

Cas looked up at him, sky eyes wide in shock. “W-wait, what?” he sputtered. “How did you know?!”

Dean let out a relaxed chuckle, leaning back on his heels. “The way you look at the girls I walk around with. The angry jealousy you have… It’s pure alpha female.”

Cas inhaled deeply, “So you’re okay with… Me? Being trans?”

The alpha nodded, hands behind his back, “Of course.”

Cas smirked, not needing to hear anymore. He gripped Dean’s shoulders and pulled him into a deep and wet kiss, taking whatever he wanted; soon feeling it be reciprocated. For many moments, there was just desire. Savage, hair-tugging, sucking-on-each-other’s-faces type desire. Dean picked up his new omega, pinning him on the wall, the new mate wrapping his legs around his. Soon there was grinding and moaning, sucking and soft biting, hands feeling whatever they could. Cas could smell the desire, feel his slick bubble out of his sweet cunt. 

Dean panted in his ear, “God, I need you, Cas.”

Cas giggled in return, “Then take me, alpha!”

The alpha stared at him for a moment, taking in the beautiful, curved face of his with the gorgeous blue eyes. If he wasn’t so horny, he could stare forever. 

Dean ripped the shirt off, running his hand down the sports bra-ed chest. He teased Cas’ nipples through the tight fabric, making them hard and pointed out to his alpha. The omega moaned from the touch, more slick producing. The liquid started to soak his pants and underwear, running down his legs. Cas ground his vulva on Dean’s growing crotch, moaning and begging for his alpha to make him cum. 

“Dean,” Cas’ carnal tone drove his alpha further into desire. “Dean, please, alpha!” he whined and begged, feeling his stomach churn. His pussy throbbed with need. 

They kissed again, in such a dirty way, tongues tangling and dancing. That’s when they heard it, making them both look up. 

“Are you serious?!” It was Sam. He looked messy and smelled of sex, making it obvious how he spent his extra time with Jessica. 

Cas was red now, seeing his friend like this with his brother. How fucking embarrassing. He put his feet down on the floor, stumbling back. 

“In the living room?!” Sam was borderline pissed. He gesticulated to the room surrounding them. 

Dean still had his hands on Cas’ waist, “You want us to go to the bedroom?”

Sam huffed with more gesticulating, “It’s not just that…! You two of all people?!”

Cas swallowed away the lump in his throat, giving a slight growl. It was a mix of anger from the cock-blocking and horny desperation. “Just leave us alone, Sam.”

Dean nodded, “What he said.” He smirked softly, “Just let have our alone time for a moment, okay?”

The beta scoffed, “I can’t believe you two.”

Cas tugged on Dean’s hand, Dean taking the message. They both headed upstairs, forgetting all about Sam and Cas’ stuff sitting in the room. 

The omega moaned as he was thrown onto the bed. Dean let his hands wander, tugging off Cas’ pants as quickly as possible. Fuck, he was so wet. The alpha pushed a finger to the new lover’s clit through his soaked underwear.

Cas gasped, “Oh, Dean!” He pushed down on his hand, “Alpha, please.”

Dean pulled his own shirt off, freckles dotting his skin like stars in the sky. He was so beautiful and his arousal smelled wonderful. Cas was so ready for him to beat his pussy. 

The alpha kissed down Cas’ waist, undoing his own pants and pulling them down. His hard cock strained against his thin underwear fabric. It needed his omega too. 

“Alpha,” Cas whined to him. “Please, Alpha. Please knot me, alpha. I need you.”

Dean pulled off the sports bras, nuzzling his face in Castiel’s full chest. The alpha pushed his fingers in his omega’s briefs, running his finger around on his clit, teasing it. He worked his mouth up from the base of the breast up to the nipple, sucking and licking. 

Cas whined, “Oh, alpha!” He pushed down on the finger, slick soaking the sheets under him. “Alpha, I need you!”

Dean hushed him, “I know… I’m going to knot you a fill you plump with my pups.” He ran his hands up and down a squirming Castiel. “That sounds good doesn’t it, omega?”

Cas nodded, “Just, please?”

Dean pulled down his own underwear, letting his hard cock spring free. He pulled down the other boy’s underwear, watching the wetness roll down his pretty pussy. A smirk spread across his face, enjoying the view. He bit his lip, bending down to lick and suck on the soft kitty. 

Cas pushed down on his face, whining for his alpha’s dick. He couldn’t stand Dean torturing him. He needed it. He needed it. 

Dean soon enough positioned himself over the younger omega, spreading his round legs and giving him what he needed. He sunk into the soft, slick, warm hole. He watched the sweet hole take his cock greedily. He watched Castiel throw his head back in pure pleasure. Finally. 

Dean didn’t take long before rearing back and pounding into his angel. Cas moaned loudly, taking the beating. Their limbs tangled in carnal desire. There was kissing and clawing, panting and hair pulling, sucking and biting. Hickeys soon covered Castiel’s breasts, finding their way to Dean’s neck. 

Bite marks trailed up Cas’ hips, up to his chest, his collarbone, and finally to his exposed and willing neck. Dean’s sharp teeth bared down his neck in such need and desire, making it draw blood. The omega moaned loudly as he was mated and taken as Dean’s. 

Dean’s knot got caught on his new mate’s hole. He was very close cumming, speeding up his thrusts. Cas bubbled up more slick on Dean’s red cock, it soon mixing with his load. 

Cas came finally, releasing the tightness in his stomach. His pussy tightened and loosened on his mate’s cock. Small whines passed his red, swollen lips. As his animalistic desire washed away, civility came back. He blinked his blue eyes and looked at Dean, touching the stinging hole on his neck. “Help me patch it up.”

Dean nodded, his knot down enough to pull out. He hopped up, pulled on his underwear and went to grab a bandage and some cleaning alcohol. He soon came back to clean up his mate’s wound and give him a cup of water. 

Cas sat up, taking the drink and wincing as Dean touched him softly. He sighed, “Dean, you mated me.”

Dean nodded and laughed softly, “Yeah, I did.” His eyes met Cas’ lovingly. He then frowned slightly, “Did you not want it?”

Cas’ eyes opened wider, “It’s not that! I was just wondering if it wasn’t just your instincts to mate me.”

Dean shook his head then kissed his cheek, “It’s not. You’re a good mate and you’ll make very nice pups in the future.”

Cas blushed, “Thank you, Dean.” He inhaled deeply when Dean was done, standing up. He turned to face his new mate, starting to get dressed again. “No offense, babe, but I came here for your brother’s party. So I’m gonna and enjoy it.” He smiled at him softly.

Dean smirked, “And I’ll be waiting in here all night.”

Cas nodded and left, buttoning up his last button. He made his way downstairs to see all his friends already fighting over the movie. He walked over and sat on the floor with Charlie and Kevin. They all were silent and eyed him. Cas knew he smelt completely acrid with sex, but he tried to keep it on the down low, ignoring it. 

Cas swallowed, looking around, “What is it, guys?”

“Cas,” Charlie started. “You just got mated to the most popular guy in school. Who’s also Sam’s brother. You’re so telling us what happened.”

The blue-eyed teenager swallowed, nodding. “Okay,” he whispered. “But later? I’m still reeling myself.”

Kevin nodded, “Yeah. I don’t think Sam wants to hear anyways. Let’s just pick a movie.”

Cas nodded, facing the TV, “Let’s.”


End file.
